The present invention concerns an inner ring on a spinning ring for ring spinning and ring twisting machines which is arranged coaxially inside the spinning ring, a gap-forming clearance being maintained, the upper traveller guide surface of which spinning ring is designed for taking up an inner traveller leg extending downward and outward.
Lubricated spinning rings for twisting machines with a concentrically arranged, tubular inner ring are already known from the Japanese Utility Publication Sho No. 43-13305/68 (comp. German DE-GM No. 71 40 330), in which arrangement the inner ring merely serves for preventing contamination of the bobbin packages by broken thread or yarn ends thrown about and soiled by dirty or greasy machine parts.
As the ring flange which takes up the circulating C-traveller, is located still too far away from the upper end of the inner ring, however, and as also the lower inner end of the traveller is located at about the same height as the upper edge of the inner ring, the inner ring cannot prevent unthreading of the thread or yarn downwardly along the inner leg of the traveller, if the thread or yarn tension is released, and especially if the thread forms loops during a stand-still of the spindle. Re-threading of the thread requires considerable operator effort and thus is extremely disadvantageous to an efficient and economic operation of a ring spinning or ring twisting machine.
Furthermore, these rings show the disadvantage that between the spinning ring and the inner ring a closed annular chamber is formed, in which traveller debris and fly waste can accumulate, and which thus require periodic cleaning. This disadvantage prevails also in a known, similar spinning ring according to U.S. Pat. No. 1,861,249.
Rings designed for non-unthreading travellers also are known (Japanese Utility Model No. 32263/74), which ring contains in the lower inner part of the flange guiding the traveller a groove, into which penetrates a traveller leg, bent intensely inwardly and ending upward. Furthermore a shoulder extending at an inclination downward and inward is provided on the inside of the ring, which shoulder serves as a traveller support surface while the spindle is at a standstill.
A disadvantage of this solution, however, is that no standard traveller readily available on the market can be applied, and that insertion and exchange of the special traveller proves difficult. Furthermore, a ring of this type does not ensure reliable prevention of the unthreading of the yarn or thread.